From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:43528) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QJRNV-0001VX-BB for qemu-devel@nongnu.org; Mon, 09 May 2011 10:24:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QJRNU-0003td-2g for qemu-devel@nongnu.org; Mon, 09 May 2011 10:24:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32684) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QJRNT-0003tW-QH for qemu-devel@nongnu.org; Mon, 09 May 2011 10:24:04 -0400 Message-ID: <4DC7F9A3.6070309@redhat.com> Date: Mon, 09 May 2011 16:26:43 +0200 From: Kevin Wolf MIME-Version: 1.0 References: <4DC6EAB5.4040607@web.de> <4DC7F668.2060205@suse.de> In-Reply-To: <4DC7F668.2060205@suse.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] ahci: crash after duplicate bh registration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Jan Kiszka , qemu-devel Am 09.05.2011 16:12, schrieb Alexander Graf: > On 05/08/2011 09:10 PM, Jan Kiszka wrote: >> Hi Alex, >> >> I've seen crashes caused by ahci_check_cmd_bh unregistering a NULL bh. >> It looks like ahci_dma_set_inactive can a called while there is already >> a bh hanging around. Patch below cures the issue, but I have no clue if >> such an invocation order is valid at all. > > It's certainly guest triggerable, so yes, let's check here. > > Acked-by: Alexander Graf Yes, the change makes sense to me. Please resend this as a proper patch, Jan. However, I still think Jan's question is valid: Is the AHCI emulation supposed to run multiple DMA requests at once using the core.c functions? I'd find it surprising if this actually worked well. Kevin